Fine particulate materials, and in particular ultra-fine particles, often become agglomerated during packaging, transport, storage, subsequent handling, etc. Agglomeration can occur for a variety of reasons, e.g., humidity, temperature, pressure. Agglomerations of particulate materials may have detrimental effects on subsequent uses of those materials. For example, agglomerates of xerographic developer material, i.e., a mixture of a carrier and toner particles, can cause banding or streaking when used in a xerographic printing device.
Agglomeration of particulate materials was found to be particularly troublesome when transporting large containers over long distances. For example, xerographic developer material is packaged in bulk in barrels and transported from the United States to India. During transport, the materials are exposed to varying levels of heat and pressure. Agglomeration often occurs resulting in print quality defects when using those materials. Although decreasing the size of shipping containers decreases the occurrences of agglomeration, it increases packaging and shipping costs.
In addition to forming agglomerated materials during transport, repackaging particulate materials may also form agglomerates. For example, after transport to its destination, developer material must be transferred from the shipping containers, e.g., barrels or buckets, to xerographic replaceable units (XRUs), cartridges or other containers. Known system 50 is an example of a device used to transfer developer material from a bulk transport or storage container 54 to XRU 52. Particulate material 56, e.g., xerographic developer material, is passed from bulk container 54 to hopper 58. Agitator motor 60 drives one or more agitators disposed within hopper 58, e.g., central agitator 62 and/or edge agitator 64. Agitators 62 and 64 to assist developer material 56 to remain evenly distributed within hopper 58 while auger 66 pushes or draws developer material 56 from hopper 58. Developer material 56 exits hopper 58 through reduced region 68 with assistance from auger 66 and falls against spinning disc 70. Spinning disc 70 imparts a centrifugal force on developer material 56 thereby throwing developer material 56 outwardly as it enters lower funnel 72. Developer material 56 then passes through reduced region 74 to neck 76 and subsequently into cartridge 52. It has been found that the foregoing arrangement results in the formation of some agglomerates, possibly due to heat and pressure generated by the interaction of auger 66 with developer material 56 within reduced region 68. As described above, the formation of agglomerates results in undesirable printing defects when a toner cartridge containing those agglomerates is used.
The present disclosure addresses a system that minimizes and/or eliminates the formation of agglomerates during transfer and packaging of particulate materials.